Book Review: Ignition and Timing.

Ummm Penguin and ignition not a marriage made in Heaven . He's so good at everything else I am baffled why this bugs him!

As an aside I have been trying without much success to determine how to set up the full range of ignition timing (user programable) without incurring great expense. Modern cars use knock sensors which allow the timing to be advanced up to the point of knock just commencing and then automatically retard the igntion until it stops pinking. (For many but not all engines this is the point at which fuel economy and power are optimised). Most of these sensors are tuned piezo microphones that bolt onto the block or head at the point where the amplitude of the knock is greatest. I've not yet found anyone who has successfully achieved this on a B series engine as there is so much mechanical clatter from the timing gear that it drowns out the knock. It may be worth experimenting up to say 3,000 rpm but above that I have my doubts. The knock sensor allows automatic compensation for changes in temperature, fuel octane, engine wear etc. The only other reliable method for detecting knock is a system I believe originated from Saab that measures the current though the spark plug. It is complicated and probably wouldn't work with an oily engine like most B series I have owned.

The distributor advance and retard was always a compromise that ran the ignition retarded as it had to be safe for the fluctuations in fuel quality, mixture settings, engine and ambient temperatures and mechanical variations from engine to engine. The biggest killer of engines is an over advanced ignition. As a result a mechanical distributor unless it is set up for each individual engine will deliver less power, the car will use more fuel and possibly experience more rapid engine wear than can be achieved by an electronic programmable unit.

Most electronic ignition after market units don't adress the timing issue, only replace the contact breaker trigger with an electronic one and some can drive a more powerful coil. For a standard B series engine apart from the convenience of not having to set the points they probably don't offer much benefit although you may have a smoother idle and better running above 5000rpm if you want to torture your treasure this way.


There is plenty of advice on how to set up the correct mixture for carb and fuel injection as the exhaust can be monitored with wideband sensors or other gas analysers. When it comes to ignition timing though it's back to the old advice of driving up a hill and advancing the ignition until pinking starts then backing off. Peter Burgess' advice is that the only way to program the timing is on a rolling road and that's not cheap. He also notes that for MGBs in his experience there is no "correct" figure for setting the timing, it varies significantly from engine to engine even though they appear the same.

Anyone have other ideas?

David